Interferometric Calibration of a Capacitance Displacement Sensor Over Short Displacement Ranges
R Koning, Ronald G. Dixson, Joseph Fu, G S. Peng, Theodore V. Vorburger
Capacitance displacement sensors, which are widely used to measure and control the true extension of piezoelectric actuators, have to be calibrated, if they are to be used for measurement purposes. We have investigated the calibration of a capacitance displacement sensor for short displacement ranges of approximately 1 mm. A linear function appears to be the most reasonable relationship of the sensor output voltage on the displacement as measured by an optical heterodyne interferometer. A complicated error structure introduced by the limited resolution and the polarization mixing of the interferometer, the phase offset between the capacitance sensor and the interferometer signal and the non-linearity of the capacitance sensor, does not lead to a significant dependence on the selected fitting procedure. However, the polarization mixing introduces a significant bias of the sensor''s sensitivity. The reproducibility, the polarization mixing and the Abbe errors constitute the major contribution of the combined measurement uncertainty of the sensitivity to the capacitance displacement sensor of 0.079%.
Proceedings of 4th Seminar on Quantitative Microscopy, K. Hasche, et al., Editors, PTB Report PTB-F-39
, Dixson, R.
, Fu, J.
, Peng, G.
and Vorburger, T.
Interferometric Calibration of a Capacitance Displacement Sensor Over Short Displacement Ranges, Proceedings of 4th Seminar on Quantitative Microscopy, K. Hasche, et al., Editors, PTB Report PTB-F-39, , 1, AU
(Accessed February 24, 2024)